--- /dev/null
+/*
+ * Copyright (C) 2019 Tomohiro Kusumi <tkusumi@netbsd.org>
+ */
+#include "../unittest.h"
+
+#ifndef CONFIG_STRSEP
+#include "../../oslib/strsep.h"
+#else
+#include <string.h>
+#endif
+
+/*
+ * strsep(3) - "If *stringp is NULL, the strsep() function returns NULL and does
+ * nothing else."
+ */
+static void test_strsep_1(void)
+{
+ char *string = NULL;
+ const char *p;
+
+ p = strsep(&string, "");
+ CU_ASSERT_EQUAL(p, NULL);
+ CU_ASSERT_EQUAL(string, NULL);
+
+ p = strsep(&string, "ABC");
+ CU_ASSERT_EQUAL(p, NULL);
+ CU_ASSERT_EQUAL(string, NULL);
+}
+
+/*
+ * strsep(3) - "In case no delimiter was found, the token is taken to be the
+ * entire string *stringp, and *stringp is made NULL."
+ */
+static void test_strsep_2(void)
+{
+ char src[] = "ABCDEFG";
+ char *string = src;
+ const char *p;
+
+ p = strsep(&string, "");
+ CU_ASSERT_EQUAL(p, src);
+ CU_ASSERT_EQUAL(*p, 'A');
+ CU_ASSERT_EQUAL(string, NULL);
+
+ string = src;
+ p = strsep(&string, "@");
+ CU_ASSERT_EQUAL(p, src);
+ CU_ASSERT_EQUAL(*p, 'A');
+ CU_ASSERT_EQUAL(string, NULL);
+}
+
+/*
+ * strsep(3) - "This token is terminated with a '\0' character (by overwriting
+ * the delimiter) and *stringp is updated to point past the token."
+ */
+static void test_strsep_3(void)
+{
+ char src[] = "ABCDEFG";
+ char *string = src;
+ const char *p;
+
+ p = strsep(&string, "ABC");
+ CU_ASSERT_EQUAL(p, &src[0]);
+ CU_ASSERT_EQUAL(*p, '\0');
+ CU_ASSERT_EQUAL(strcmp(string, "BCDEFG"), 0);
+ CU_ASSERT_EQUAL(*string, 'B');
+
+ p = strsep(&string, "ABC");
+ CU_ASSERT_EQUAL(p, &src[1]);
+ CU_ASSERT_EQUAL(*p, '\0');
+ CU_ASSERT_EQUAL(strcmp(string, "CDEFG"), 0);
+ CU_ASSERT_EQUAL(*string, 'C');
+
+ p = strsep(&string, "ABC");
+ CU_ASSERT_EQUAL(p, &src[2]);
+ CU_ASSERT_EQUAL(*p, '\0');
+ CU_ASSERT_EQUAL(strcmp(string, "DEFG"), 0);
+ CU_ASSERT_EQUAL(*string, 'D');
+
+ p = strsep(&string, "ABC");
+ CU_ASSERT_EQUAL(p, &src[3]);
+ CU_ASSERT_EQUAL(*p, 'D');
+ CU_ASSERT_EQUAL(string, NULL);
+}
+
+static struct fio_unittest_entry tests[] = {
+ {
+ .name = "strsep/1",
+ .fn = test_strsep_1,
+ },
+ {
+ .name = "strsep/2",
+ .fn = test_strsep_2,
+ },
+ {
+ .name = "strsep/3",
+ .fn = test_strsep_3,
+ },
+ {
+ .name = NULL,
+ },
+};
+
+CU_ErrorCode fio_unittest_oslib_strsep(void)
+{
+ return fio_unittest_add_suite("oslib/strsep.c", NULL, NULL, tests);
+}